In a typical co-axial flashlamp, light from only one surface, either the inner or outer surface, of the lamp is used while the other surface is covered with a solid metal foil that functions as a current return. This structure causes approximately half of the generated light to be lost. The light is lost because it cannot pass through the optically dense plasma in the discharge annulus after being reflected by the shiny return surface. Consequently, the only practical contribution of the reflected light is to raise the plasma temperature. But the plasma temperature in a co-axial flashlamp is already higher than desirable and any further rise in it is not welcome because the high temperature plasma is rich in ultraviolet radiation which pumps most dyes inefficiently and contributes to dye degradation.